One clinical trial currently underway in the National Drug Abuse Treatment Clinical Trials Network (CTN) is testing the effectiveness of Buprenorphine/Naloxone-facilitated rehabilitation (Bup/Nal)in opioid dependent adolescents/young adults. Bup/Nal in combination with psychosocial treatment has already been shown to improve treatment outcomes in adults. This new combined therapy offers hope for opiate dependent young people who have been growing in number and have very few prospects for treatment or recovery. Given that Bup/Nal has recently been approved for addiction treatment, quantifying the cost-effectiveness of this new intervention will be critical to the ultimate success of the diffusion of this new intervention. The specific aims of this protocol are to: (1) Perform a comprehensive economic analysis of buprenorphine/naloxone-facilitated rehabilitation for opioid dependent adolescents/young adults by analyzing medical costs of treatment, cost-effectiveness, and cost-benefits. (2) Illustrate the methods for economic analysis of substance abuse interventions in a clinical trial and facilitate replication of these methods by other investigators in the CTN network. The long-term objectives of this study are to (1) provide information to promote efficient treatment options for opioid dependent youth; and (2) advance and disseminate the methods of economic evaluation in clinical trials of substance abuse treatment to the point where they are as rigorous as the methods for evaluating effectiveness. The CTN is an ideal setting to meet these objectives because the CTN provides a pool of clinical trials from which to test these methods in practice, a networked set of researchers, and a broad set of participating community treatment providers that strive to improve the economic efficiency of treatment delivery.